Great Planes P-51D Mustang 40 Kit - GPMA0175 - Manual (Page 41)

Now that you have the basic airframe nearly completed,
this is a good time to balance the airplane laterally (side-to-
side). Here is how to do it:
D 1. Temporarily attach the wing and engine (with muf-
fler) to the fuselage.
D 2. With the wing level, lift the model by the engine
propeller shaft and the bottom of the rudder (this may require
two people). Do this several times.
D 3. If one wing always drops when you lift, it means that
side is heavy. Balance the airplane by gluing weight to the
other wing tip. NOTE: An airplane that has been laterally
balanced will track better in loops and other maneuvers.
FINAL SANDING
Nearly every imperfection in your wood structure will
show through the covering material; therefore, before cover-
ing, you should make a final check of the entire structure. Fix
any "dings," then sand the entire structure smooth using
progressively finer grades of sandpaper.
Recommended Covering Sequence:
1. 1/2" Strips as described in above note
2. Rudder left side
3. Rudder right side
4. Bottom of elevators
5. Top of elevators
6. Stab bottom
7. Stab top
8. Fuse bottom
9. Wing fillets*
10. Fuse sides
11. Fuse top
12. Fin left side
13. Fin right side
14. Ends of ailerons
15. Bottom of ailerons
16. Top of ailerons
17. Aileron openings in wing
18. Scoop and fairings (on bottom of wing)
19. Bottom of left wing panel
20. Bottom of right wing panel
21. Top of left wing panel (overlap covering 1/4" at
wing LE)
22. Top of right wing panel (overlap covering 1/2" at the
center and 1/4" at the LE)
*When covering concave surfaces, follow the iron with
a damp cloth, pressing the covering down.
COVERING
Because it is assumed that you have had some previous
model building experience, we won't go into detail in regard
to the covering procedure. Follow the instructions included
with your covering material.
NOTE: When covering the fin and stab, begin by
applying 1/2" wide strips of covering in the comers
between the fin and stab, and (on the bottom of the stab)
between the stab and the fuse sides. Next, cover the stab
and fin with pre-cut pieces that have a straight edge to
overlap (1/8"+ overlap) the strips you previously applied.
DO NOT, under any circumstances, attempt to cut
the covering material after it has been applied to the
fin and stab, except around the leading and trailing
edges and the tip. Modelers who do this often cut
through the covering and part-way into the balsa stab.
This can weaken the stab to the point where it may fail in
flight!
The P-51D Mustang prototype was first covered com-
pletely with Super Monokote aluminum (with the exception
of the rudder). Next, the aluminum was carefully cut away in
the areas of the black and white "invasion stripes" and the
anti-glare panel on the top front of the fuselage.
GLUE THE HINGES
NOTE: Here is the recommended general sequence for
installing the elevator, rudder and hinges...
A. Attach elevators to stab with hinges.
B. Install a small 1/4" balsa filler behind the elevator,
leaving room for unobstructed movement of the 1/8"
wire elevator connector.
C. Cover the filler with covering material, and add fu-
elproofing if necessary.
D. Attach rudder to fin with hinges, and install the tailgear
at the same time.
D 1. Lay the rudder, elevators and ailerons on the plans
and mark on the leading edge of each part the locations of the
hinges, torque rods and tailgear. Now use a sharp Xacto knife
to cut slits in the covering at the hinge locations. Trial fit the
hinges to make sure you have "found" the slots which you
previously cut. In the same manner, slit the covering at the
hinge locations in the wing, stab and fin TE. Also cut the
covering away from the torque rod and tailgear slots.
41